US Navy canceling program to turn gas-guzzling destroyers into hybrids

The Navy is canceling a program to install fuel-efficient hybrid electric drives in 34 destroyers, leaving only one destroyer with the technology, the Navy confirmed in a statement.

Citing “department priorities,” the service requested $6.3 million for 2018 to finish the installation on the destroyer Truxtun, but has zeroed out funding in 2019 and in the out years. The service has spent about $52 million on the program to date. The whole program was expected to cost $356.25 million, according to the Navy’s FY2017 budget submission.

“Based on the Department’s priorities, President’s Budget 2019 removes funding from Hybrid Electric Drive program in FY 2019,” said Lt. Lauren Chatmas in a statement. “There are no further procurements or installations planned beyond DDG-103 in the Future Years Defense Program.”

The Navy will use Truxtun as a test bed to see if the technology pays off in the long run, Chatmas continued.

“Installation on DDG-103 is in progress and when installation is complete, operational usage of HED on DDG-103 will be monitored and evaluated to determine the effectiveness of HED. This will inform future decision on the fielding of HED.”

The program developed with L-3 was designed to switch power to the drive shaft, which turns the ship’s propellers, from the main LM2500 gas turbine motors to the ship’s electrical generators at speeds below 13 knots. At those speeds the ship could perform night steaming, ballistic missile defense or anti-submarine operations, but not keep up with the speedy carriers.

As the program began to materialize and development progressed, a number of problems began to materialize, according to a former Navy official who spoke on background. Foremost among them was the intense electrical load that running the drive system on the ship’s two running generators was putting on the ship.

Destroyers have three generators, two of which run while a third remains in standby, which rotates through while generators are down for maintenance or in case of an emergency. Running the electrical motor that turned the shaft while also running the ship’s power-hungry radars and related systems maxed out the capacity of those generators.

“At that point you are a light switch flipping on away from winking out the whole ship,” the official said.

Furthermore running the generators at that load wasn’t exactly as fuel efficient as they had hoped it would be.

Those issues, while valid, could probably have been solved through engineering, said Bryan Clark, a retired submarine officer and analyst with the Center for Strategic and Budgetary Assessments.

To Clark, canceling the program seems a bit shortsighted, given the potential for the technology to make a real difference in fuel efficiency in future ships and classes.

“If it’s a money thing, that’s one thing,” he said. “If it’s either this or invest in over-the-horizon anti-surface weapons, well OK. But if it’s this or another science and technology or research and development program — one of the major challenges we have is figuring out how to be more efficient at certain profiles. That would be worth knowing.”